Magnetocaloric effect in Laves-phase rare-earth compounds with the second-order magnetic phase transition: Estimation of the high-field properties

Abstract High-field magnetocaloric effect of the rare-earth Laves-phase compounds, which show the second-order magnetic phase transition at low temperatures, has been studied theoretically and experimentally. Both direct and indirect methods are used to characterize the high-field properties of the adiabatic temperature change, ΔT ad , and the magnetic entropy change, ΔS mag , for TbNi 2 and DyNi 2 compounds, which order ferromagnetically below 37 and 22 K, respectively. Experimental data are compared with theoretical results obtained in the frame of the microscopic model which takes into account the Zeeman exchange interaction and the crystal electric field anisotropy. The high-field magnetocaloric properties near the phase transition are also discussed in the framework of the Landau theory for the second-order phase transitions.